As a child, Congressman John Lewis, the son of sharecroppers from Pike County, Alabama, was turned away from his local public library—it was for whites only. He didn’t return until 1998, when he was invited to a book signing for his memoir, “Walking with the Wind.” At the 2015 New Yorker Festival, Lewis spoke with David Remnick about his early days in the civil-rights movement, his interactions with Malcolm X and John F. Kennedy, and how he survives in Congress alongside colleagues who “hate government.”